Maintaining the proper axial internal clearance or end play of the rotor relative to the stator of an electric motor is very important for successful operation of sleeve bearing motors. Insufficient clearance causes excessive wear of thrust surfaces and may prevent low torque motors from starting. Excessive clearance also causes objectionable end bumping noise at motor start up and also can create alignment problems for external shaft mounted components such as gears, blowers and impeller. Approaches to the end play problem have been by the machining of the parts and the use of shims which add considerable cost to a motor. The present invention overcomes the problem by the use of a thrust collar and bushing ultrasonically welded together and located under controlled conditions with respect to the main frame and bearing on the shaft which provides the desired clearance of the bearing to permit easy motor starting and yet limited enough to lower end bumping noise to acceptable levels. By use of the invention more open toleranced parts can be used than is generally permitted with shims and machining of parts.